An integrated circuit (IC) typically includes a number of semiconductor devices otherwise known as IC devices. One way to represent an IC device is with a plan view diagram referred to as a layout diagram, or IC layout diagram. An IC layout diagram is hierarchical and includes modules which carry out high-level functions in accordance with the IC device's design specifications. The modules are often built from a combination of cells that can include both standard and custom cells, each of which represents one or more semiconductor structures.
Cells are configured to provide common, low-level functions, often performed by transistors based on gate regions that intersect active regions, sometimes known as oxide definition (OD) regions. The elements of a cell are arranged within a cell boundary and electrically connected to other cells through interconnect structures.